The management of Simple Rental Flats (*Rusunawa*), as a form of public service, continues to face challenges in maintaining the sustainability of their residential function—particularly regarding facility maintenance, oversight, and repair. Issues such as suboptimal infrastructure maintenance, the lack of periodic facility inspections, and limited maintenance budgets highlight challenges regarding the institutional capacity of the *Rusunawa* management agency. This study aims to analyze the capacity of the Public Works and Spatial Planning Agency in improving the quality of *Rusunawa* management in Sukabumi City. A descriptive method with a qualitative approach was employed, utilizing data collection techniques such as observation, interviews, and documentation. The analysis utilized Horton et al.’s (2003) organizational capacity theory, which comprises five dimensions: human resources, infrastructure, strategic leadership, management programs and processes, and networks and relationships. The findings indicate that the Agency's capacity for *Rusunawa* management is supported by its organizational ability to coordinate, monitor, and address facility-related issues. However, constraints remain, including limited resources, a suboptimal preventive maintenance system, and a need to strengthen management processes for facility upkeep. This study underscores that improving the quality of *Rusunawa* management depends not only on the physical condition of the buildings but also on the management agency's capacity to manage resources and sustainably deliver public housing services.